Keratitis Due to Fusarium langsethiae: Clinical Profile, Molecular Identification, and Susceptibility to Antifungals

Abstract

We report a case of keratitis due to Fusarium langsethiae in a 56-year-old man. The patient presented with pain and tearing of 10 days duration in the right eye, which had sustained a paddy stalk injury. On examination, a hypopyon corneal ulcer was noted in the right eye. Multiple scrapings were obtained from the affected part of the cornea. A lactophenol cotton blue wet mount and a Gram-stained smear of scrapings were made. Scrapings were also inoculated on various culture media, including Sabouraud dextrose agar (SDA). A fungal etiology was sought by conventional microbiological techniques and polymerase chain reaction. In vitro susceptibility testing was performed by an agar dilution method. Direct microscopy of corneal scrapings revealed septate hyphae, leading to initiation of intensive topical therapy with natamycin (5 %). However, the keratitis progressed, necessitating therapeutic penetrating keratoplasty. White, powdery-like colonies, with abundant aerial mycelium, were recovered on SDA from corneal scrape material. Based on macroscopic and microscopic morphological features, the isolated fungus was initially identified as a Fusarium species. Sequence analysis of the 28S rRNA region of the fungal genome led to a specific identification of F. langsethiae. Antifungal susceptibility testing results suggested that the strain isolated was susceptible to voriconazole, ketoconazole, and itraconazole. To our knowledge, this is the first reported case of keratitis due to F. langsethiae; attention is drawn to the unique characteristics of the fungal isolate, difficulties in identification and non-responsiveness to medical therapy.

Identificación de microorganismos presentes en la atmósfera baja de una zona industrial del área metropolitana de Monterrey

“…Estos resultados nos indican que hay una moderada contaminación y carga microbiana por la diversidad de especies presentes en el ambiente, lo que se puede asociar a ciertas enfermedades respiratorias, alergias, etc. Por ejemplo, Aspergillus puede provocar sinusitis alérgica y onicomicosis [7]; mientras que Fusarium también causa queratitis, una infección en los ojos [8].…”

<p>Clinical outcome after air-assisted manual deep anterior lamellar keratoplasty for fungal keratitis poorly responsive to medical treatment</p>

“…Fungal keratitis remains an important disorder in clinical ophthalmology because of difficulty in its diagnosis, and some patients do not respond to medical treatment using antifungal local and systemic agents 1. Therapeutic keratoplasty (TKP) has been reported for sight-threatening situations in cases of suppurative keratitis with impending corneal perforation or intraocular inflammatory invasion with typical symptoms such as hypopyon or corneal hyphae 2–4. Two surgical methods, penetrating keratoplasty (PKP) and lamellar keratoplasty (LKP), have been considered for these disorders, and the surgical outcomes with each procedure have been reported.…”

Diagnosis of Fusarium Infections: Approaches to Identification by the Clinical Mycology Laboratory

“…In many countries, fungal keratitis is treated with natamycin, that is effective against most but not all, Fusarium species, e.g. [ 18 ]. Detailed studies on antifungal susceptibility profiles emphasize the need for species-level identification for best-adapted treatment strategies [ 5 ].…”